Boiler-flue scraper.



H. SMITH.

BOILER FLUE SGRAPER.

'APPLIOATION FILED APR.29, 1909.

Patented Jan. 4, 1910.

TUE.

HENRY SMITH, OF THE UNITED STATES NAVY.

BOILER-FLUE SCRAPER.

To all whom it may concern:

Be it known that I, HENRY SMITH, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York, anda chief machinist in the U. S. Navy, have invented certain new anduseful Improvements in Boiler-Flue Scrapers; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

My invention relates to an improvement in scrapers.

The object of my invention is to provide an adjustable scraper which isespecially adapted for cleaning boiler tubes of water tube boilers, andwhich will remove the small blisters inside of the tube, which holdpockets of magnetic iron OXlCl and carbonic acid gas.

lVith this object in view, my invention consists in the construction andcombinations of parts as hereinafter described and claimed.

In the accompanying drawings-Figure l is a side elevation partly insection, of my improved scraper. Fig. 2 is a perspective view of one ofthe springs. Fig. 3 is a side view of the same. Fig. at is a perspectiveview on a smaller scale of the central securing rod. Fig. 5 is aperspective view of the complete device. Fig. 6 is a cross section onthe line 66 of Fig. 5. Fig. 7 is a side view of one of the scrapingdevices, and Fig. 8 is an end view of the same.

This scraper is composed of a central metal rod, shown in Fig. 4:, theinterior of which, as shown at a, is cylindrical and provided withscrew-threaded ends Z) and 0, collars (Z and c, and squared portions fand 9. On the end 0, which is adapted to be pushed into a boiler tube, acap or nut h is adapted to be screwed, which is tapered as shown at 2'and is provided with a screw-threaded recess j, adapted to engage theend 0 of the rod, and is cut away, forming a blunt, conical portion 7a,and cut away still farther to provide a larger conical portion m. 0represents a similar nut adapted to screw on to the threaded portion 1)and provided with a central screw-threaded portion and two conicalportions similar to those on the nut h. The screw-threaded portion 6 isof such a length that when the nut 0 is screwed home, or nearly so, thepart b will project consider- Speeification of Letters Patent.

Application filed April 29, 1909.

Patented Jan. 4., 1910. Serial No. 493,025.

ably through this nut, and on this projecting portion a nut 39 isadapted to be screwed and act as a jam nut against the part 0, when thedesired tension and diameter is obtained. The interior of the nut 7 isprovided with two screw-threaded portions, a larger portion adapted toengage with the screwthreaded portion 6 and a smaller screw-threadedportion 9, into which the end of a handle may be screwed.

1" represents a series of springs, four being preferably used, which areheld between the collars (Z and 0, each of said springs being providedwith a central boss 8 on its outside. These springs are preferably madeas shown in Figs. 2 and 3, although the exact form of said springs isnot material.

t represents one of the scraping plates, provided with a central recess10, adapted to engage the projection s on the corresponding spring, andhaving its ends tapered off. Made integral with this plate t, orattached thereto in any suitable manner, are the scrapers, preferablymade of steel, and consisting of a central portion '0 and raisedportions near each end thereof. These raised portions or cutters consistof a curved member '10, having sharp edges and composed of drop-forgingsof hardened steel, and a central portion 0a tapering off as shown at 3The scraper blades are curved at each end to prevent disengagementbetween the collars and caps when the scraper is adjusted for tubes of alarger diameter. Cutters of mild steel as well as of hardened steel maybe used to suit the condition of the deposit in the boiler tubes.

As shown in Fig. 5, the parts to on the four scraping plates are soarranged as to overlap at their ends, so that no portion of the tubewill escape the scraping action. It should be noted that the scrapersare square in cross section, so that they are self sharpening, that theyare not perpendicular to the axis of the tool so that the ends ofadjacent cutters overlap, the result being that no part of the tube isleft unscraped when the tool is shoved or pulled through a boiler tube.The cutter nearest the stock is slightly larger than the one nearest theend, so that each set of cutters does independent work each time thescraper is pushed through.

The operation is as follows: A long rod with a hand grip at the end isscrewed into the sleeve 9. The tool is then pushed through the tube andpulled back, while a hose is played in the back header, the waterwashing out the deposit and keeping both front and rear cutting edges ofthe cutter clean. If, after the tool has made one passage through thetube, the latter is not perfectly clean, the operator adjusts the sizeof the tool by screwing out the nuts h and 0, and the scraping operationis repeated.

By the use of this tool in the manner described, the small blisters onthe inside of the tube, which contain magnetic oxid of iron and carbonicacid gas, can be completely and efficiently reinoved, leaving theinterior of the tube as clean as a new rifle barrel.

I claim:

A scraper comprising a central rod provided with screw-threaded ends,with collars located inside of said screw-threaded ends, and withflattened portions inside of said collars, a plurality of springs, one,

adapted to engage each of the flattened portions of said rod and restagainst said collars, each of said springs being provided with a centralboss on the outside, scraper plates, one engaging each of said springs,and having a recessed portion adapted to engage the boss on thecorresponding spring, each of said scraper plates being provided withcutters, said cutters having curved ends, and nuts adapted to screw ontothe screw-threaded portions of said rod, each nut being hollowed awayand provided with two conical portions on its interior, against whichsaid collars and the rounded ends of said scraper plates abutrespectively, substantially as described.

In testimony whereof, I atfix iny signature, in presence of twowitnesses.

' HENRY SMITH. Vitnesses B. TARDY, W. R. SCOFIELD.

